Broadcast History - October 22

Broadcast History - October 22

Postby jon » Wed Oct 21, 2020 9:17 pm

In 1940, CBR (later CBU) Vancouver signed on its first CBC LPRT (Low-Powered Relay Transmitter): in Revelstoke on 840 KHz with 20 watts. By the mid-1960s, there were more than 70 of them throughout British Columbia, all on AM and almost all of them with 40 watts. The most popular frequency was 860 KHz, a Canada/Mexico clear channel after the Great Frequency Shuffle of 1941. In most isolated B.C. communities, it was important to choose a frequency with minimal skywave interference from other stations, as it didn't take much, on a good DX night, to cause interference with a lowly 40 watt local signal. Not to mention the fact that much CBC programming in those years had quiet passages which meant that it did not take much signal strength from other stations to cause havoc.


For many years after World War II, LPRTs provided the only daytime radio reception for many isolated communities, especially in British Columbia and "North of 60" (Yukon and the then-much larger Northwest Territories). Some of these communities have been used for the control group for many landmark Psychological studies on the effects of television on children, as many LPRT communities were relatively late (1960s) getting television service.

At least one network of LPRTs even got its own programming. When I was working at CFPR (CBC) Prince Rupert in 1972, we produced a daily live one hour program ("Line Up") from the Production Studio for the dozen or so LPRTs fed by CFPR, along the Yellowhead Highway to Prince George. CFPR aired a live local program during the same time period, 5:10 to 6:00 p.m. weekdays. Local correspondents in each community provided pre-recorded reports.

In case of an emergency during the overnight period, when CFPR was off the air, the LPRTs were connected directly to CFPR's feed from CBU Vancouver. And now it can be told: I did the Saturday morning show, and, against my boss' orders, would begin feeding the LPRTs at 5:00 a.m., even though I didn't sign on CFPR until just before the 6:00 a.m. CBC News from Toronto.

Despite their very small power, LPRTs could be heard in Vancouver after midnight Sunday nights when other stations on the same frequency were off the air for transmitter maintenance. Up to the late '60s, CBC Radio ran 24/7. After that, you could even hear the Open Carrier all night as LPRT transmitters were never shut off, except for maintenance.

CBXB Banff was one of those LPRTs on 860 KHz, but it simulcast CBR Calgary, so was on the air one hour earlier than the B.C. LPRTs after the CBC quit running 24/7 in the late 1960s. The QSL card below is from one such reception in Vancouver.


In 1959, Irene Madoche began her first day of work as Receptionist at Edmonton's CJCA AM & FM, and VE9AI on shortwave; all three stations were simulcast at that time. She retired more than a half a century later, when CJCA-FM was K-97 with the call letters CIRK-FM. Still as Receptionist in the West Edmonton Mall home of Newcap Edmonton, which also includes CFCW-AM and CKRA-FM (Capital-FM).
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